The group is comprised of 59 affiliate companies in fields such as heavy machinery, construction and finance, which operate in more than 90 countries and territories.

South Korea's Fair Trade Commission says the group's total assets were worth 348 trillion won, or more than 300 billion dollars, in April 2016. The figure is the largest among the country's conglomerates.

The Samsung Group's exports are said to amount to 20 percent of the country's total.

Samsung Electronics is the core of the group. It has grown into a global company through sales of smartphones, semiconductors and home appliances. It has been competing fiercely for market share with Apple and other smartphone makers.

Samsung Electronics Vice Chairman Lee Jae-yong is 48 years old.

He has studied business administration at Japan's Keio University.

Lee has been involved in his company's expansion in the semiconductor and display businesses. He became vice chairman in 2012.

After his father, the company's chairman, fell ill with myocardial infarction in 2014, he has led management as a de-facto leader.

There's concern that Lee's arrest has tarnished Samsung's image and could affect its management, as well as the South Korean economy as a whole.